Authenticity indicator

Abstract

An authenticity indicator that is difficult to be forged and whose authenticity can be confirmed easily and accurately is provided. The authenticity of the authenticity indicator 10 can be checked by making light enter the authenticity indicator 10 from front side and observing the light emerging from the front side or rear side. The authenticity indicator comprises a polarized-light selectively reflecting layer 30 that reflects a specified polarized component of incident light, and a transmission volume hologram layer 20 disposed on the front side of the polarized-light selectively reflecting layer 30. According to this authenticity indicator, its authenticity can be checked accurately by making use of its first authenticity recognition function attributed to the diffracting action of the transmission volume hologram layer and its second authenticity recognition function attributed to the polarized-light selectivity of the polarized-light selectively reflecting layer.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is based on Japanese Patent Application No. 2006-098452 filed on Mar. 31, 2006, and the entire contents of Application No. 2006-098452 is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to an authenticity indicator to be used to indicate that an article or the like is authentic, and particularly to an authenticity indicator whose authenticity can be checked easily and accurately. The present invention also relates to an authenticity checking method for checking the authenticity of an authenticity indicator to be used to indicate that an article or the like is genuine, and an authenticity checking system useful for checking the same, and particularly to an authenticity checking method and system by which the authenticity of the authenticity indicator can be checked easily and accurately. [0004] 2. Related Art [0005] Hologram labels, etc. u...

AI Technical Summary

Benefits of technology

[0032] In the authenticity checking system according to the present invention, the transmission volume hologram layer may have an image recorded therein, and the checking unit may be configured to check the authenticity of the authenticity indicator by confirming whether the image is reconstructed by the light to be received by the light-receiving device or not, or by confirming whether the image is reconstructed by the light to be received by the light-receiving device or not and also observing the brightness of the reconstructed image. According to such an authenticity checking system of the invention, the image recorded in the transmission volume hologram layer can be recognized by the front side light-receiving device placed in front of the authenticity indicator or by the rear side light-receiving device placed at the rear of the authenticity indicator, so that the authenticity of the authenticity indicator can be checked more accurately. Further, by taking the brightness of the reconstructed image into account, the authenticity of the authenticity indicator can be checked with still higher accuracy.

[0033] Furthermore, the authenticity checking system according to the present invention may further comprise a light source that emits light on the authenticity indicator from the front side. According to such an authenticity checking system of the invention, the light-receiving device can receive an increased amount of light, so that the authenticity of the authenticity indicator can be checked more accurately. And if the light source is made to emit on the authenticity indicator a specified polarized-light component or light in a specified wavelength range, the authenticity of the authenticity indicator can be checked more accurately.

[0034] In this authenticity checking system according to the present invention, the light source may be configured to emit light on the authenticity indicator so th

Problems solved by technology

Further, since the recording of an image to give a transmission volume hologram and the duplication of a transmission volume hologram require sophisticated techniq

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